You could Modify the Neo (Matrix) trench coat pattern that Simplicity carries in thier costume section. Basically cut back the lapels a touch and make a front panel with buttons, then modify the collar. Make a muslin mock first to make sure everything fits right cause vinyl can be mean to work with. (tissue paper between layers to prevent some stretching and paper clips instead of pins to hold layers together are some sugguestions.)
_________________
Taking Commissions .I specialize in kimonos, Bleach, and I am expanding my repetoire. I have done Trench Coats. I make quaility pieces that can be used everyday

Please leave me a messages we can talk about what you need. SanguineSpinner.etsy.com for the quick and easy kimono purchase.
www.racheldesade.deviantart.com to see some of my work.